U.S. patent number 5,689,020 [Application Number 08/614,005] was granted by the patent office on 1997-11-18 for high temperature chlorination process for the preparation of polychloroolefins.
This patent grant is currently assigned to LaRoche Industries Inc.. Invention is credited to C. Bradford Boyce.
United States Patent |
5,689,020 |
Boyce |
November 18, 1997 |
High temperature chlorination process for the preparation of
polychloroolefins
Abstract
A process is disclosed for preparing a compound selected from
the group consisting of 1,1,3,3-tetrachloropropene and
1,3,3,3-tetrachloropropene. The process comprises a. admixing a
hydrocarbon compound selected from the group consisting of propene,
1-chloropropene, 3-chloropropene, 1,1-dichloropropene,
1,3-dichloropropene, 3,3,-dichloropropene, 1,1-dichloropropane,
11,2-dichloropropane, 1,3-dichloropropane, 1,1,3-trichloropropene,
1,3,3-trichloropropene, 3,3,3-trichloropropene, and mixtures
thereof with an inert diluent gas; b. preheating said mixture to
from about 300.degree. C. to about 400.degree. C. and then mixing
it with chlorine gas; and c. thermally treating the mixture of step
b. at a temperature of from about 400.degree. C. to about
600.degree. C. The desired tetrachloropropene is then
separated.
Inventors: |
Boyce; C. Bradford (Baton
Rouge, LA) |
Assignee: |
LaRoche Industries Inc.
(Atlanta, GA)
|
Family
ID: |
24459520 |
Appl.
No.: |
08/614,005 |
Filed: |
March 11, 1996 |
Current U.S.
Class: |
570/216 |
Current CPC
Class: |
C07C
17/10 (20130101); C07C 21/04 (20130101); C07C
17/10 (20130101); C07C 21/04 (20130101) |
Current International
Class: |
C07C
21/00 (20060101); C07C 21/04 (20060101); C07C
17/10 (20060101); C07C 17/00 (20060101); C07C
021/04 () |
Field of
Search: |
;570/216,226 |
Other References
CA 69: 86337 , 1967. .
CA 69: 51544 , 1967..
|
Primary Examiner: Wu; Shean C.
Attorney, Agent or Firm: Hammond; Richard J.
Claims
I claim:
1. A process for preparing a compound selected from the group
consisting of 1,1,3,3-tetrachloropropene and
1,3,3,3-tetrachloropropene by
a. admixing a hydrocarbon compound selected from the group
consisting of propene, 1-chloropropene, 3-chloropropene,
1,1-dichloropropene, 1,3-dichloropropene, 3,3,-dichloropropene,
1,1-dichloropropane, 1,2-dichloropropane, 1,3-dichloropropane,
1,1,3-trichloropropene, 1,3,3-trichloropropene,
3,3,3-trichloropropene, and mixtures thereof with an inert diluent
gas;
b. preheating said mixture to from about 300.degree. C. to about
400.degree. C. and then mixing it with chlorine gas; and
c. thermally treating the mixture of step b. at a temperature of
from about 400.degree. C. to about 600.degree. C.
2. The process according to claim 1 wherein said compound is
1,1,3,3-tetrachloropropene.
3. The process according to claim 2 wherein said hydrocarbon
compound is mixed with a diluent prior to said thermal
treatment.
4. The process according to claim 3 wherein from about three to
about four moles of diluent per mole hydrocarbon compound is
employed.
5. The process according to claim 1 wherein said thermal treatment
is at a temperature of fro about 480.degree. C. to about
520.degree. C.
6. The process according to claim 1 wherein said compound is
1,3,3,3-tetrachloropropene.
7. The process according to claim 6 wherein said hydrocarbon
compound is mixed with a diluent prior to said thermal
treatment.
8. The process according to claim 7 wherein from about three to
about four moles of diluent per mole hydrocarbon compound is
employed.
9. The process according to claim 8 wherein said thermal treatment
is at a temperature of from about 480.degree. C. to about
520.degree. C.
10. A process for preparing an olefinic chlorocarbon selected from
the group consisting of 1,1,3,3-tetrachloropropene and
1,3,3,3-tetrachloropropene by
a. admixing one mole of a hydrocarbon compound selected from the
group consisting of propene, 1-chloropropene, 3-chloropropene,
1,1-dichloropropene, 1,3-dichloropropene, 3,3,-dichloropropene,
1,1-dichloropropane, 1,2-dichloropropane, 1,3-dichloropropane,
1,1,3-trichloropropene, 1,3,3-trichloropropene,
3,3,3-trichloropropene, and mixtures thereof with from about three
to about four moles of an inert diluent at about 300.degree. C. to
about 400.degree. C. to form a mixture of said hydrocarbon compound
with said gas;
b. mixing said admixture with chlorine gas;
c. thermally treating the mixture of step b. at a temperature of
from about 480 .degree. C. to about 520.degree. C.; and
d. separating said olefinic chlorocarbon.
Description
FIELD OF INVENTION
This process relates to a process for the preparation of
1,1,3,3-tetrachloropropene and 1,3,3,3-tetrachloropropene by the
high temperature chlorination of propene, monochloropropenes,
dichloropropenes and trichloropropenes where the chloropropenes
have no chlorine on the number 2 carbon. The process may also
utilize 1,2-dichloropropane.
BACKGROUND OF THE INVENTION
The need exists for an inexpensive source of
1,1,3,3-tetrachloropropene as the starting material for the
manufacture of HFC-245fa (1,1, 1,3,3-pentafluoropropane), a "third
generation" CFC-11 (CCl.sub.3 F) replacement in the fluorocarbons
industry. One way to obtain the desired tetrachloropropene is to
eliminate the elements of HCl from 1,1,1,3,3-pentachloropropane by
treatment with base or heating with a Lewis acid like ferric
chloride, general methods well established in the art. The
pentachloropropane can be prepared by the free radical coupling of
carbon tetrachloride with vinyl chloride using a copper
chloride/amine catalyst (Bull. Chem. Soc. Japan 43 1127 (1970) or
an initiator such as benzoyl peroxide (Organic Reactions Vol 13
Chap. 3, 1963). These routes involve two chemical steps and
significant processing problems. Carbon tetrachloride may also be
coupled with acetylene using a free radical catalyst to yield
1,3,3,3-tetrachloropropene (U.S. Pat. No. 3,338,981 [1967]), which
will spontaneously rearrange with acid, but the yield is poor. Even
less commercially attractive routes to tetrachloropropene have been
reported using 3,3-dichloroacrolein and acetyl chloride with
aluminum trichloride catalyst (Bull. Soc. Chim. France 2147 (1963),
1,1,3-trichloropropene and potassium thioacetate or sodium sulfide
followed by chlorine (French Pat. 1,496,124 and 1,496,180 [1966]),
and the pyrolysis of 1,1,2,3-tetrachlorocyclopropane (Chem. Com.
1081 [1967]).
In a typical chlorination of olefinic hydrocarbons, chlorine is
added across the double bond to produce dichloro-substituted
hydrocarbons, i.e., propene gives good yields of
1,2-dichloropropane. However, the reaction of chlorine with propene
is changed from addition to substitution by operating at
400.degree. to 600.degree. C. yielding allyl chloride with good
selectivity. This reaction is the basis of the commercial
manufacture of allyl chloride. The primary byproducts are 1- and
2-chloropropene, 1,3- and 3,3-dichloropropene, and
1,2-dichloropropane (Ind. Eng. Chem. 31[2] 1530 (1939)).
High temperature chlorination of 1- or 3-chloropropenes yield
allylic substitution products 1,3- and 3,3 -dichloropropenes. 1,1-,
1,3- and 3,3-dichloropropenes yield 1,1,3- and
1,3,3trichloropropenes with high selectivity (J.Am. Chem. Soc. 75
1392 (1953)).
High temperature chlorination of 1- or 3-chloropropenes yield
allylic substitution products 1,3- and 3,3-dichloropropenes. 1,1-,
1,3- and 3,3-dichloropropenes yield 1,1,3- and
1,3,3-trichloropropenes with high selectivity (J.Am. Chem. Soc. 75
1392 (1953)).
It should be noted that U.S. Pat. No. 4,319,062 discloses that
dichloropropenes are relatively stable to conditions that may
thermally crack 1,2-dichloropropane. This latter compound produces
predominately 1- and 3-monochloropropenes under high temperature
cracking conditions.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the process of the present invention, the starting materials are
hydrocarbon compounds selected from the group consisting of
propene, 1-chloropropene, 3-chloropropene, 1,1-dichloropropene,
1,3-dichloropropene, 3,3-dichloropropene, 1,1-dichloropropane,
1,2-dichloropropane, 1,3-dichloropropane, 1,1,3-trichloropropene,
1,3,3-dichloropropene, and 3,3,3-trichloropropene.
In carrying out the process of the present invention, one or more
of the starting materials listed above is diluted with 3 to 4 molar
equivalents of an inert diluent gas such as nitrogen or,
preferably, carbon tetrachloride. This mixture is preheated to
300.degree. to 400.degree. , preferably 340.degree. to 360.degree.
C. and passed into a reactor where it is mixed with about 110% of
the theoretical amount of chlorine. Depending on the feed, the
amount of chlorine may be adjusted up or down to maximize the yield
of 1,1,3,3-tetrachloropropene. The reaction is exothermic. The
mixture within the reactor is maintained between 400.degree. and
600.degree. C., preferably 480.degree. to 520.degree. C. The size
of the reactor is chosen to provide a residence time of 0.1 to 10
seconds, preferably 2 to 5 seconds. The exit gases (which contain
the desired product) are immediately quenched preferably with a
water spray. The resulting aqueous HCl and organic layers are
separated. The organic layer is stripped of solvent and low boiling
substances and distilled to obtain the desired
tetrachloropropene.
EXAMPLES
The reactor comprises a nickel tube 2 cm. I.D..times.50 cm.
surrounded by a tube furnace and maintained at a temperature of
about 500.degree. C. The temperature is measured by thermocouple
within the reactor. The material to be chlorinated is pumped into
an silicone oil heated evaporator at a rate of about 0.25 moles per
minute. The resulting vapor is admixed with gaseous chlorine with
the flow controlled by a mass flow controller. The reactants are
mixed in a 0.2 cm. diameter jet attached directly to the reactor.
After exiting the reactor, the reaction products are passed thru a
water-cooled condenser and into a 500 ml flask. The chlorinated
products are then isolated by conventional methods. The effluent,
largely HCL vapor, is scrubbed with water.
* * * * *